Determination of total petroleum hydrocarbons in soil from different locations using infrared spectrophotometry and gas chromatography

Abstract

Total petroleum hydrocarbons (TPH) are important environmental contaminants which are toxic to human and environmental receptors. Several analytical methods have been used to quantify TPH levels in contaminated soils, specifically through infrared spectrometry (IR) and gas chromatogra-phy (GC). Despite being two of the most used techniques, some issues remain that have been inadequately studied: a) applicability of both techniques to soils contaminated with two distinct types of fuel (petrol and diesel), b) influence of the soil natural organic matter content on the results achieved by various analytical methods, and c) evaluation of the performance of both techniques in analyses of soils with different levels of contamination (presumably non-contaminated and po-tentially contaminated). The main objectives of this work were to answer these questions and to provide more complete information about the potentials and limitations of GC and IR techniques. The results led us to the following conclusions: a) IR analysis of soils contaminated with petrol is not suitable due to volatilisation losses, b) there is a significant influence of organic matter in IR analysis, and c) both techniques demonstrated the capacity to accurately quantify TPH in soils, irrespective of their contamination levels.

Potential of integrated field spectroscopy and spatial analysis for enhanced assessment of soil contamination: A prospective review

“…Alternative extraction processes involve supercritical fluid extraction where CO 2 under high pressure is used as a solvent (Dawson et al, 2004). In later years (1990s onwards), BTEX (the aromatic hydrocarbons benzene, toluene, ethylbenzene and xylene) were the focus of analyses because these hydrocarbons are of environmental concern and were measurable in the field using newly developed field-portable GCs with photo-ionisation detectors (PID) highly sensitive to these compounds (Sadler and Connell, 2003;Paíga et al, 2012). Although soil moisture lowers the response to these organic analytes, the capacity to make determinations on-site after recovering soil air by probe or by taking soil for headspace analyses meant huge savings in time and sample processing.…”

“…For example, lower molecular weight aromatics can be quite soluble and have been found in groundwater close to oil-fields (Zarrella et al, 1967). Therefore, aromatic hydrocarbons such as benzene are likely to be transported in soil by 'water washing' if not volatilised where soil-adsorption is poor (Paíga et al, 2012). Fig.…”

“…Conventionally, hydrocarbon contamination has been determined by laborious solvent extraction of known amounts of soil followed by gas chromatographic (GC) separation and analysis usually with a flame ionisation detector (FID) or mass spectrometer (Sadler and Connell, 2003;Paíga et al, 2012). This provides a relative quantification of the range of hydrocarbon compounds persisting in the soil.…”

Identification and Phylogenetic Analysis of Two Marine Petroleum-Degrading Yeasts from South China Sea Offshore Based on Magnetic Nanoparticles Extraction

“…The petroleum degradation rates for the strains were respectively determined with ultraviolet spectrophotometry method, using automatic infrared oil analyzer with GB/T16488-1996 as standard. 29 …”

Artificial Intelligence Assisted Mid-Infrared Laser Spectroscopy In Situ Detection of Petroleum in Soils

“…For example, certain soils contain traces of oil even after cleanup and are not monitored because oil concentration is considered low (~600-20,000 mg·kg -1 , 0.06-2%) [51,52], rendering them as "decontaminated." In accordance with Dutch legislation (VROM, 1987) [53], there are three limit values of total petroleum hydrocarbons mass per mass of soil: reference (S: 10 mg·kg −1 ; 0.001%), intervention (I: 1000 mg·kg −1 ; 0.1%), and alert (T: 505 mg·kg −1 ; 0.05%). The S value indicates the level at which the soil and groundwater are considered "clean".…”